The present invention relates to a luminous composite fabric and garment endowed with luminous properties.
Research is currently being conducted concerning fabrics and garments endowed with luminescent properties in order to improve visibility and enhance safety when work is performed under conditions of poor lighting or when nighttime work is performed outdoors, and to achieve better aesthetic properties under conditions of poor lighting.
The following types of such luminous fabric are known: products obtained by coating or imprinting a fabric surface with a coating preparation containing a luminescent substance, or impregnating the fabric therewith (conventional products (1)), products obtained by bonding luminescent strips to fabric surfaces (conventional products (2)), and products in which luminescent materials are used as the filling tapes during garment manufacture, and the resulting garments are worn by being turned inside out as needed (conventional products (3)).
A specific example of conventional product (1) is disclosed in Japanese Unexamined Utility Model Application 57-65914 (reference 1), which describes a product obtained by completely or partially coating or imprinting a glove surface with a photo-storage pigment. In addition, Japanese Unexamined Utility Model Application 7-12418 (reference 2) discloses a completely colored luminous product obtained by dyeing a garment with a luminous pigment substantially free from radioactive materials. Japanese Unexamined Patent Application 10-292257 (reference 3) discloses a luminescent fibrous structure whose apparent surface area constitutes no more than 0.7 of the actual surface area and in which the fabric surface is coated with a prescribed amount of luminous pigment. Japanese Unexamined Patent Application 11-50378 (reference 4) discloses a breathable, waterproof, luminescence-regenerating, reflective printed fabric in which the fabric surface is coated in a dry state with a resin layer containing aluminum, silver or another light-reflecting substance, and the resin layer is then imprinted with a resin layer containing fine luminescent powder and glass beads.
A specific example of conventional product (2) is disclosed in Japanese Unexamined Utility Model Application 58-135408 (reference 5), which describes a luminescent piece of clothing obtained by bonding luminescent strips at prescribed locations on the obverse side of a piece of fabric.
A specific example of conventional product (3) is disclosed in Japanese Unexamined Utility Model Application 59-123125 (reference 6), which describes a garment in which a luminescent tape is attached as a sealing tape to the insides of garment seams, and the garment is turned inside out during nighttime emergencies to utilize the luminescence capabilities of the garment.
A drawback of the luminescent gloves of reference 1 or the luminescent fibrous structures of reference 3 is that the luminescent layers peel off over time due to outside exposure, and the luminescence capabilities thereof risk being compromised by the soiling of the surface layer and cannot be maintained for a sufficiently long time. Another drawback is that the aesthetic qualities of the products are compromised because the luminescent layers are exposed to the outside. Yet another drawback is that design limitations make it impossible to adapt these products to uniforms and other types of fixed-design clothing. In addition, the luminescent fibrous structures of reference 3 are three-dimensional, and hence their application was limited to breast sections, back sections, and other garment sections where said structures do not inhibit movement during wear, making it impossible to provide acceptable visibility at certain angles.
Similarly, the garment of reference 2 loses some of its luminescence capabilities over time due to the soiling of the surface layer, and thus cannot be regarded as acceptable because this garment remains luminescent for only a short time. Another drawback of the garment disclosed in reference 2 is that acrylic resin or another binder must be used in order to bond a luminous pigment to the fiber surface with sufficient durability, but a fabric obtained using such a binder is much less acceptable in terms of hand and moisture permeability. In addition, fabric colors are limited to light tones in order to provide adequate luminescence capabilities, imposing design limitations. The colors of the luminescent pigments themselves are also limited, making it difficult to obtain light color tones (such as white) and creating problems when such products are used, for example, to manufacture white rainwear for traffic control officers.
The luminescent printed fabric of reference 4 is obtained by employing a two-step process to coat the fabric surface with a resin, but this structure prevents a thin resin layer from being formed on the fabric, and is thus disadvantageous in that the moisture permeability or hand of the fabric are severely compromised. The use of polyurethane resin, which has excellent moisture permeability, for the resin layer has been suggested as a way of improving the moisture permeability of printed fabrics, but because the polyurethane resin takes up moisture, swells, and allows the moisture to penetrate into the film, the luminescent pigment is exposed to the moisture and hydrolyzed, losing some or all of its luminescence capabilities.
Because the luminous clothing of reference 5 is configured such that the luminescent layer is exposed on the clothing exterior, its luminescence capabilities decrease over time due to the soiling of the surface layer or the peeling off of the luminescent layer in the same manner as above, and can therefore be sustained only for a short time. The garment loses some of its hand and wear comfort due to the stiffening of the areas occupied by the luminescent strips, the luminescent material can be utilized only partially, the range of design options is limited because the luminescent layer must be exposed to the outside, and there is a risk that the aesthetic qualities will be compromised.
In the garment described in reference 6, the seams alone are provided with a luminescent tape, so the resulting luminescence is insufficient for providing good visibility. Cost and waterproofness considerations commonly dictate that a waterproof garment be patterned with a minimum possible number of seams. In addition, luminescent tape for stitches and jointed portions must remain inconspicuous because of design considerations. Such placement cannot provide good visibility. Another drawback is that when a luminescent tape is fused over a jointed portion, the joints and ends of the tape stand out, and the external appearance of the product is severely compromised. The luminophors used are commonly photo-storage materials, but because the garment of reference 6 can exhibit luminescence capabilities only after being turned inside out, the luminescent tape remains on the inside of the garment during normal wear and cannot store light because of the lack of exposure. A resulting drawback is that luminescence cannot be achieved in the absence of a light source for exciting the luminescent tape in an emergency.
Therefore, an object of the present invention, which was perfected in view of the above-described drawbacks, is to provide a luminous fabric and garment that have excellent luminescent properties under conditions of poor lighting, that lose their luminescent properties only slightly due to wear degradation and the like during prolonged use, that have the same color tone and design as regular fabrics and garments during day use, and that possess excellent aesthetic qualities and are free from design limitations.
These and other purposes of the present invention will become evident from review of the following specification.
An important feature of the luminous composite fabric pertaining to the present invention is that the reverse side of the fabric is covered partially or completely with a backing member containing a luminescent substance.
Another important feature of the luminous composite fabric pertaining to the present invention is that the reverse side of the fabric is covered partially or completely with a backing member via an adhesive, and a luminescent substance is added to the adhesive and/or the backing member.
Light emitted by the backing member containing a luminescent substance or by the adhesive containing a luminescent substance passes through the fabric and reaches the obverse side, providing excellent visibility under conditions of poor lighting. In addition, a fabric is commonly abraded, soiled, or the like from the obverse side, but because the backing member containing a luminescent substance or the adhesive containing a luminescent substance is disposed on the reverse side of the fabric, it is possible to prevent outside abrasion, soiling, or the like from occurring, so the luminescence capabilities are affected only slightly. In addition, the backing member containing a luminescent substance is provided on the reverse side of the fabric in the manner described above, preventing the design on the obverse side of the fabric from being affected in any way and making it possible to create the same pattern as that used on a regular fabric under conditions of poor lighting.
The fabric and the backing member may be brought into direct contact or disposed with an interposed adhesive or other member. The backing member may be a film, a fabric, a net, or a material applied in dots or stripes to the fabric.
The term xe2x80x9creverse side of fabricxe2x80x9d refers to the portion on the reverse side that remains invisible from the outside when the luminous composite fabric is used, and is the surface facing the body when the luminous composite fabric is used as part of a garment. Conversely, the term xe2x80x9cobverse side of fabricxe2x80x9d refers to the surface on the obverse side that is visible from the outside when the luminous composite fabric is used, and is the surface disposed on the obverse side when the fabric is used as part of a garment.
The term xe2x80x9cluminescent substancexe2x80x9d refers to a light-emitting substance such as a substance exhibiting fluorescence or phosphorescence. Particularly preferred are photo-storage substances that store optical energy and continue to emit light after the optical stimulus is removed.
A substance containing an aluminate compound is preferred as the luminescent substance.
A material having a light transmittance of 10% or greater at 350 nm, and 15% or greater at 500 nm, should preferably be used as the luminous composite fabric pertaining to the present invention. This is because such a fabric is better suited for transmitting the light emitted by a luminescent substance or the optical energy provided to the luminescent substance.
In the luminous composite fabric pertaining to the present invention, the backing member should preferably be composed of a resin material. This is because a resin material is easier to add to a luminescent substance.
In the luminous composite fabric pertaining to the present invention, the resin material should preferably be composed of a moisture-permeable resin. This is because when, for example, the luminous composite fabric is used as part of a garment or the like, the garment remains breathable and comfortable to wear as long as the backing member remains moisture permeable.
In the luminous composite fabric pertaining to the present invention, the moisture-permeable resin should preferably have a stratified structure. Examples of stratified structures include film products and layers formed by coating fabrics with resins.
A stretched porous polytetrafluoroethylene film (hereinafter xe2x80x9ca porous PTFE filmxe2x80x9d) can be cited as a preferred example of the moisture-permeable resin. A porous PTFE film is waterproof and has excellent moisture permeability and flexibility, and is therefore preferred when, for example, the luminous composite fabric is used as part of a garment.
The porous PTFE film can be obtained by laminating two or more layers. When, for example, the porous PTFE film is obtained by laminating two or more layers, a pinhole or other defect formed in one layer of the porous PTFE film may compromise its waterproofness, but the other layer of the porous PTFE film will still remain waterproof. In preferred practice, a hydrophilic moisture-permeable resin (for example, urethane) is laminated to the porous PTFE film. This option is preferred because the hydrophilic moisture-permeable resin can prevent soil from depositing on the porous PTFE film.
Another preferred feature of the present invention is that the moisture-permeable resin be composed of a plurality of layers, the fabric-side layer of these plurality of layers contain a luminescent substance, and the layer on the opposite side be substantially devoid of a luminescent substance.
For example, a porous PTFE film containing a luminescent substance, and a porous PTFE film devoid of a luminescent substance may be laminated together such that the porous PTFE film devoid of a luminescent substance is disposed on the side opposite the fabric. This arrangement makes it easier for the obverse side of the fabric to be illuminated because the porous PTFE film on the side opposite the fabric reflects light emitted by the porous PTFE film on the fabric side.
Another feature of the present invention is that the plurality of layers should preferably be laminated such that the moisture-permeable resin substantially devoid of a luminescent substance is caused to partially penetrate into the moisture-permeable voids of the moisture-permeable resin layer containing a luminescent substance.
For example, a porous film containing a luminescent substance may be used as a moisture-permeable resin layer in the above-described manner, and a coating may be formed such that a hydrophilic moisture-permeable resin is caused to partially penetrate into the pores of the porous film.
Still another feature of the present invention is that the moisture-permeable resin containing a luminescent substance should preferably be a stretched porous polytetrafluoroethylene film, and the moisture-permeable resin layer substantially devoid of a luminescent substance should preferably be urethane.
The luminous composite fabric pertaining to the present invention is that the backing member should also have adhesive properties and occupy 5-90% of the surface area on the reverse side of the fabric. This is because an excessively narrow bonding area fails to yield adequate adhesive strength. Another reason is that a backing member exhibiting adhesive properties commonly has low moisture permeability, and an excessively wide bonding area yields low moisture permeability and compromises wear comfort when the luminous composite fabric is made into a garment. Examples of such backing members include meshes, dots, and stripes.
Yet another preferred feature of the luminous composite fabric pertaining to the present invention is that the surface of the backing member farther away from the fabric be provided with a protective layer. In other words, the outer reverse surface should preferably be provided with a protective layer. The protective layer may be a fabric or a film and may be attached to the backing member directly or via an adhesive.
The main point of the garment pertaining to the present invention is that the above-described luminous composite fabric is used over all or part of the garment surface, with the obverse side of the fabric positioned on the side away from the body. This garment remains highly visible under conditions of poor lighting because a luminous composite fabric capable of emitting light is used on the obverse side of the fabric in the manner described above.